Instruction Manual
D103288X012
249VS Sensor
July 2018
8
Replacing the Displacer, Cotter Spring, Stem End Piece, and Displacer
Spud
The cotter spring (key 8), the ball on the displacer rod/driver assembly (key 14), and the stem end piece or displacer
stem connector (key 18) may be either too worn for a secure connection or so clogged or corroded that the displacer
does not pivot properly. Replace these parts, as necessary.
CAUTION
If the displacer is to be disconnected from the displacer rod/driver assembly before being removed from the process vessel,
provide a suitable means of supporting the displacer to prevent it from dropping into the process vessel and being
damaged.
1. After following the proper procedure to remove the torque tube arm assembly and the displacer from the process
vessel, move the sensor assembly to a suitable maintenance area. Support the assembly to avoid damage to the
displacer, displacer stem, displacer rod assembly, and associated parts.
2. Reach the cotter spring, displacer spud, ball end of the displacer rod/driver assembly, stem end piece, or displacer
stem connector as follows:
Remove the process vessel bolting and pull out the torque tube arm assembly (key 1). The inside of the process
vessel wall will cause the displacer to swing up so it can be pulled out through the vessel opening.
3. Remove the cotter spring to free the displacer or stem end piece from the ball end of the displacer rod/driver
assembly. Lift the displacer or stem end piece from the ball.
4. Replace worn or damaged parts as necessary. Return the displacer or stem end piece to the displacer rod/driver
assembly. Install the cotter spring.
5. Install the controller/transmitter. Calibrate the controller/transmitter following the procedures given in the
controller/transmitter instruction manual.
Replacing the Displacer Rod/Driver Assembly
The ball on the displacer rod/driver assembly (key 14) may be either too worn for a secure connection or so corroded
that the displacer does not pivot properly. Replace the displacer rod/driver assembly, if necessary.
CAUTION
If the displacer is to be disconnected from the displacer rod before being removed from the process vessel, provide a
suitable means of supporting the displacer to prevent it from dropping into the process vessel and being damaged.
1. After following the proper procedure to remove the torque tube arm assembly and the displacer from the process
vessel, move the sensor assembly to a suitable maintenance area. Support the assembly to avoid damage to the
displacer, displacer stem, displacer rod assembly, and associated parts.
2. Remove the controller/transmitter and displacer (key 9).
3. Remove the nuts (key 13) and retaining flange (key 12) at the end of the torque tube arm.
4. Remove the positioning plate (key 21) by freeing its two lugs.
The vertical lug fits into a hole in the flange of the torque tube arm (top of figure 7, left). The horizontal lug (hidden
behind the screwdriver at the bottom of figure 7, left) fits into a slot in the outer tube end of the torque tube
assembly (the figure 7 exploded view shows this lug to the right of the outer tube end).
